diff --git a/Makefile b/Makefile
index 5543c9e7..9d14578e 100644
--- a/Makefile
+++ b/Makefile
@@ -281,6 +281,7 @@ C_FILES = \
 	freebsd/kern/uipc_mbuf.c \
 	freebsd/kern/uipc_mbuf2.c \
 	freebsd/kern/uipc_socket.c \
+	freebsd/kern/uipc_sockbuf.c \
 	freebsd/dev/usb/usb_busdma.c \
 	freebsd/dev/usb/usb_core.c \
 	freebsd/dev/usb/usb_debug.c \